Which chemical reaction produces ortho-hydroxybenzoic acid, the primary reaction product used as a raw material for medications?
Solution:
The correct answer is Kolbe’s reaction (Kolbe–Schmitt reaction).
Explanation:
Ortho-hydroxybenzoic acid (salicylic acid) is prepared by heating sodium phenoxide with carbon dioxide (CO₂) under pressure (about 4–7 atm) at around 400 K. The intermediate formed is sodium salicylate, which on acidification gives salicylic acid.
C₆H₅ONa + CO₂ → C₆H₄(OH)COONa →(H⁺)→ C₆H₄(OH)COOH
Importance:
Salicylic acid is an important compound used in the manufacture of several medicines:
- Aspirin (acetylsalicylic acid): Used as a pain reliever, fever reducer, and anti-inflammatory drug
- Methyl salicylate: Used in topical ointments for muscle pain relief
Why other options are incorrect:
- Reimer–Tiemann reaction: Produces salicylaldehyde (–CHO group), not salicylic acid (–COOH group)
- Stephen reaction: Used to prepare aldehydes from nitriles
- Friedel–Crafts reaction: Used for alkylation or acylation of aromatic rings, not for forming hydroxy acids
Correct Answer: Kolbe’s reaction
Important Questions from Chemical Reaction
Food containing oil and fat, when kept for a longer time, causes a change in its taste and smell due to the process of __________.
Which chemical is widely used to unclog drains and sinks?
.......... is a chemical process or a reaction between fuel (hydrocarbon) and oxygen producing heat and light energy resulting in a flame.
A solution of which of the following is needed to test the presence of proteins?
Curd is formed with the help of ............. bacteria.
